Determining condition and quality of foodstuffs is important to the consumer and to marketability of the foodstuff. Making an assessment of foodstuff quality is essential to guarantee a safe and wholesome product for human consumption. In the case of seafood, current quality management systems, i.e., the National Oceanic and Atmospheric Association (NOAA) Seafood Inspection program and the federal Hazard Analysis and Critical Control Point (HACCP), rely heavily on good record keeping.
A direct measurement of the condition of fish by biological or chemical analysis is not practiced because of complexity, cost, and time. Therefore, more subjective methods, such as Quality Index Method (QIM), are used throughout the catch to consumption chain. These subjective practices are primarily based on olfactory, tactile, and visual scores of fish. The time period after harvest is important, because fish tissue begins to decompose after catching, harvesting, and killing, and shelf life thereafter is dependent on species and post harvest practices. A shorter shelf life can result from temperature, handling, and product abuse.
The professional care of the product from harvesting to consumption can be monitored by studying the electrical properties of the product. Measuring electrical properties of fish tissue is a quantitative method of evaluating the fish after harvest. Electrical measures can quantitatively show that colder temperatures slow the natural degradation process of tissues that involve the production of protease enzymes that denature the proteins located in the cell membrane. Freezing on the other hand, involves the induction of large osmotic differences that rupture the cell membranes after thawing. This causes an influx of electrolytes from the cytoplasm into interstitial spaces and reducing shelf life significantly.
It would be desirable to have a method and device to aid in the inspection and certification of harvested food for human consumption.